PICTURE: Prototype hybrid airship flies

A 15.2m (50ft)-long prototype for a 95m airship has now been flown 22 times and its developer Hybrid Air Vehicles has submitted bids for US military contracts, including the Long Endurance Multi-INT Vehicle (LEMV) programme for the US Army.

The army's LEMV wants an untethered and unmanned "hybrid airship" that can operate up to 20,000ft, have a roundtrip range of 4,025km (2,175nm), average cruise speed of 30kt (55km/h), carry a minimum payload of 1,135kg (2,500lb) and be able to keep station for three continuous weeks.

Founded by private investors, the Bedfordshire, UK-based company's prototype first flew in July 2008. To date, according to the company, the test programme has successfully demonstrated the vectoring and bow thruster systems. Another focus has been vertical take-off and landing operations. Its proposed Condor 404 vehicle could meet the LEMV criteria. The prototype's design team members have built more than 20 airships in 20 years.

The airship will use one-third of the fuel of equivalent fixed-wing aircraft

"This is not just theory. The structure [now] is built-in. An air cushion landing system sucks the aircraft down to the deck. Everything has been flown in full size or prototype," says Hybrid Air Vehicles chairman Rod Sinclair.

The company claims its vehicles can stay aloft even if punctured and will use one-third of the fuel of an equivalent fixed-wing aircraft.

As well as the LEMV programme, the company is also bidding for the US Marine Corps Immediate cargo unmanned air system programme, which requires a vehicle capable of remote location deployment by February 2010 or sooner that is able to deliver up to 9,090kg within 24h on a round tip of 280km, hover at a 12,000ft density altitude and fly at a density altitude of 15,000ft fully laden.